package de.tc.stammdatenverwaltung.functions;

import java.io.UnsupportedEncodingException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

public class EncWrapper
{

  Cipher ecipher;
  Cipher dcipher;
  // 8-byte Salt
  byte[] salt =
  {
    (byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32,
    (byte) 0x56, (byte) 0x35, (byte) 0xE3, (byte) 0x03
  };
  // Iteration count
  int iterationCount = 19;

  EncWrapper(String passPhrase)
  {
    try
    {
      // Create the key
      KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
      SecretKey key = SecretKeyFactory.getInstance(
              "PBEWithMD5AndDES").generateSecret(keySpec);
      ecipher = Cipher.getInstance( key.getAlgorithm() );
      dcipher = Cipher.getInstance( key.getAlgorithm() );

      // Prepare the parameter to the ciphers
      AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);

      // Create the ciphers
      ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
      dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
    }
    catch (java.security.InvalidAlgorithmParameterException e){ System.out.println( e.getMessage() ); }
    catch (java.security.spec.InvalidKeySpecException e){ System.out.println( e.getMessage() ); }
    catch (javax.crypto.NoSuchPaddingException e){ System.out.println( e.getMessage() ); }
    catch (java.security.NoSuchAlgorithmException e){ System.out.println( e.getMessage() ); }
    catch (java.security.InvalidKeyException e){ System.out.println( e.getMessage() ); }
  }

  public String encrypt(String str)
  {
    try
    {
      // Encode the string into bytes using utf-8
      byte[] utf8 = str.getBytes("UTF8");

      // Encrypt
      byte[] enc = ecipher.doFinal(utf8);

      // Encode bytes to base64 to get a string
      return new sun.misc.BASE64Encoder().encode(enc);
    }
    catch (javax.crypto.BadPaddingException e){ System.out.println( e.getMessage() ); }
    catch (IllegalBlockSizeException e){ System.out.println( e.getMessage() ); }
    catch (UnsupportedEncodingException e){ System.out.println( e.getMessage() ); }
    catch (java.io.IOException e){ System.out.println( e.getMessage() ); }
    return null;
  }

  public String decrypt(String str)
  {
    try
    {
      // Decode base64 to get bytes
      byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);

      // Decrypt
      byte[] utf8 = dcipher.doFinal(dec);

      // Decode using utf-8
      return new String(utf8, "UTF8");
    }
    catch (javax.crypto.BadPaddingException e){ System.out.println( e.getMessage() ); }
    catch (IllegalBlockSizeException e){ System.out.println( e.getMessage() ); }
    catch (UnsupportedEncodingException e){ System.out.println( e.getMessage() ); }
    catch (java.io.IOException e){ System.out.println( e.getMessage() ); }
    return null;
  }
}
